This invention relates generally to mounting fixtures, and more specifically to a mounting fixture used to fabricate a plurality of different turbine engine components.
In known turbine engines, sometimes it is necessary to form openings that extend through a portion of the turbine. For example, sometimes is it necessary to drill openings through vertical flanges extending from a turbine casing. To drill horizontally, the drilling assembly must first be secured into position relative to the flange. To prevent movement of the turbine during the drilling, dowels are inserted through pre-formed apertures defined in the flanges. However, it may be difficult to secure the same drilling assembly to different engines, as the turbine engines may be sized differently, i.e. with different arc lengths, bolt spacings, and bolt radii, for example. Moreover, even within the same turbine such dimensions may vary from one portion of the engine to another portion of the turbine.
To align the drilling assembly with a portion of the turbine, at least some drilling assemblies use a mounting fixture. At least some known mounting fixtures are unitarily fabricated and are sized to enable the fixture to be coupled to the casing. As such, generally, a different fixture is needed for each different size of turbine or for each area of the engine. For example, a first fixture may be used on a portion of the casing formed with a first bolt spacing and a second fixture may be required on those portions of the casing formed with a second bolt spacing. In another example, one fixture is sized for use with a turbine rated for a first operation, while another fixture must be configured for use with a turbine rated for a second operation.
In one known fabrication method used to form apertures in a casing flange, several mounting fixtures with varying dimensions and configurations must be used to complete one drilling job. As such, several mounting fixtures unique to that turbine must be fabricated. Such requirements increase the costs and time of the aperture fabrication process. Furthermore, known fixtures are typically fabricated from solid steel, and, as such, may be awkward to move around and may be a hazard to those working with the fixtures.